Field of the Invention
The present invention relates to a cap for a container in general, and has particular application in the field of vials, such as glass vials, containing a pharmaceutical product.
Background Art
Containers such as injection vials or cartridges comprising pharmaceuticals are increasingly becoming the target of counterfeiters. The counterfeiters either re-use already consumed original components or use standard packaging components which are available on the market and which are identical or look-alikes of the components used by the original product manufacturers.
Such vials or cartridges are typically made of glass or plastic and often have a standardized size and shape (without being limited to standardized sizes and shapes). The vials or cartridges typically have a neck having an opening which is sealed by a stopper (typically made of rubber) plugged into the opening of the neck to allow for a sterile storage of the liquid in the container. In order to access the pharmaceutical product in the interior of the container, a needle may be pierced through the rubber stopper, and the needle is then moved further into the interior of the container until the tip of the needle extends into the pharmaceutical product stored in the interior of the container. The pharmaceutical product can then exit from the interior of the container through the needle. For example, when using a syringe the syringe needle is pierced through the rubber stopper, and the container is then turned upside down to prevent air from being drawn into the syringe. The needle tip extends into the liquid, and the syringe plunger is then moved backwards thus creating an underpressure that causes the liquid to be drawn from the interior of the container into the syringe.
The container typically not only comprises the rubber stopper but in addition comprises a ferrule fixedly holding the rubber stopper in position to make sure that the container remains sealed so as to prevent the pharmaceutical product stored in the interior of the container from getting contaminated or being exposed to the ambient environment. The ferrule typically is a metal shell (e.g. made from aluminum) having an upper surface and a skirt depending downwards from the upper surface. The lower end of the skirt is crimped to engage a rim on the outer wall surrounding the opening of the container. Alternatively, the ferrule may be a plastic shell which is snapped on to engage the rim on the outer wall surrounding the opening. In both cases, the ferrule fixedly retains the stopper in place in the opening to keep the interior of the container sealed.
Attached to the ferrule before first use of the container is an overseal button that covers both the rubber stopper and the upper surface of the ferrule. Known overseal buttons are translucent and colorless in their entirety, or are opaque and colored. The color may represent the specific type of pharmaceutical product, or may represent a specific concentration of a pharmaceutical product. The overseal button is connected to a tamper evidence mechanism. To use the container for the first time, the user has to remove the overseal button from the ferrule in order to expose a central portion of the rubber stopper. Upon removal of the overseal button, the tamper evidence mechanism is irreversibly damaged. Typically, upon removal of the overseal button a centrally arranged circular portion of the upper surface of the rubber stopper is exposed so that subsequently a needle can be pierced through this exposed portion of the rubber stopper to allow the pharmaceutical product to exit from the interior of the container through the needle.
Counterfeiting may occur either by refilling the original container and re-arranging the overseal button of the original product manufacturer to again cover the upper surface of the ferrule and the (already damaged) tamper evidence mechanism, or by using a new container having a shape which is identical or very similar to that of the original container, and by re-arranging the overseal button of the original product manufacturer to cover the upper surface of the ferrule. Although this re-arrangement of the overseal button is not easy to perform, if it is done in a skillful manner the overseal button remains arranged on the upper surface of the ferrule and gives the user the impression that the container is a container from the original product manufacturer and has not been opened before. In case of an overseal button which is translucent and colorless in its entirety, the user may be able to determine whether the tamper evidence mechanism is damaged or not, however, there is no possibility to use the color of the overseal button for identifying the type of pharmaceutical product, the concentration, or whatever. In case of an overseal button which is opaque and colored in its entirety, the user may be able to identify the type of product, the concentration, or whatever, but cannot see whether the tamper evidence mechanism is damaged or not. Once the user has removed the overseal button (regardless of whether this has been done from the original product or from a counterfeit product), the tamper evidence mechanism is damaged in any event. Typically, upon first opening of the non-used container removal of the overseal button creates a sound, for example a “click” indicating that the tamper evidence mechanism has been irreversibly damaged. However, in case the re-arrangement of the overseal button is performed skillfully, upon removal of the re-arranged overseal button a “click” may also be created. Therefore, it is very difficult for the user to determine whether the respective “click” comes from a first removal of the overseal button from the ferrule or from the removal of a skilfully re-arranged overseal button from the ferrule—after removal of the overseal button the tamper evidence mechanism is damaged in any event.
Therefore, there exists a need for a cap that allows the user before removal of the overseal button to determine whether or not the container has not been opened before, while at the same time preserving the option to identify the product manufacturer on the overseal button and to use colors for identifying the type of product, the product concentration, or whatever.